Unexpected sound omissions are signaled in human posterior superior temporal gyrus: an intracranial study.

Context modulates sensory neural activations enhancing perceptual and behavioral performance and reducing prediction errors. However, the mechanism of when and where these high-level expectations act on sensory processing is unclear. Here, we isolate the effect of expectation absent of any auditory evoked activity by assessing the response to omitted expected sounds.

Desloratadine shows no effect on performance during 6 h at 8,000 ft simulated cabin altitude.

Introduction: Sustained vigilance is required by pilots and crew during flight; therefore, the use of antihistamines with sedating properties is widely prohibited. The purpose of this study was to determine the effects of desloratadine, a long-acting, nonsedating antihistamine, on healthy volunteers placed under conditions of simulated cabin pressure.

Methods: In a double-blind crossover study, 21 subjects randomly received single doses of desloratadine 5 mg, diphenhydramine 50 mg (active control), and placebo on different days separated by washout periods of 7 d.

Personal Active Noise Reduction with integrated Speech Communication devices: development and assessment.

Active noise reduction is a successful addition to passive eardefenders for improvement of the sound attenuation at low frequencies. Assessment methods are discussed, focused on subjective and objective attenuation measurements, stability, and on high noise level applications. Active noise reduction systems are suitable for integration with an intercom.

Contribution of spectral cues to human sound localization.

The contribution of spectral cues to human sound localization was investigated by removing cues in 1/2-, 1- or 2-octave bands in the frequency range above 4 kHz. Localization responses were given by placing an acoustic pointer at the same apparent position as a virtual target. The pointer was generated by filtering a 100-ms harmonic complex with equalized head-related transfer functions (HRTFs).

Cognitive suppression of tilt sensations during linear horizontal self-motion in the dark.

On the basis of models of otolith functioning, one would expect that, during sinusoidal linear self-motion in darkness, percepts of body tilt are experienced. However, this is normally not the case, which suggests that the otoliths are not responsive to small deviations from the vertical of the gravito-inertial force vector acting on them. Here we show that this is incorrect.

Sound localization in the presence of one or two distracters.

Localizing a target sound can be a challenge when one or more distracter sounds are present at the same time. This study measured the effect of distracter position on target localization for one distracter (17 positions) and two distracters (21 combinations of 17 positions). Listeners were instructed to point to the apparent position of a train of 30-ms noise bursts, presented at 1 of 85 positions in virtual free field.

Fault management in supervisory control: the effect of false alarms and support.

Automation has changed the role of human operators from direct manual control to supervision. Their main task is to monitor whether system performance remains within pre-specified ranges and intervention is only required in unusual situations. One of the consequences is a loss of situation awareness, which significantly affects performance in abnormal, time-critical situation.

Effects of two types of intra-team feedback on developing a shared mental model in Command & Control teams.

In two studies, the effect of two types of intra-team feedback on developing a shared mental model in Command & Control teams was investigated. A distinction is made between performance monitoring and team self-correction. Performance monitoring is the ability of team members to monitor each other's task execution and give feedback during task execution.

Multichannel speech intelligibility and talker recognition using monaural, binaural, and three-dimensional auditory presentation.

In a 3D auditory display, sounds are presented over headphones in a way that they seem to originate from virtual sources in a space around the listener. This paper describes a study on the possible merits of such a display for bandlimited speech with respect to intelligibility and talker recognition against a background of competing voices. Different conditions were investigated: speech material (words/sentences), presentation mode (monaural/binaural/3D), number of competing talkers (1-4), and virtual position of the talkers (in 45 degrees-steps around the front horizontal plane).

Motion sickness.

The number of recently published papers on motion sickness may convey the impression that motion sickness is far from being understood. The current review focusses on a concept which tends to unify the different manifestations and theories of motion sickness. The paper highlights the relations between ergonomic principles to minimise motion sickness and the concept predictions.

On-line driver workload estimation. Effects of road situation and age on secondary task measures.

In order to develop a driver-car interface that adapts the presentation of messages generated by in-vehicle information systems to driver workload, two experiments investigated potential determinants of driver visual and mental workload as indicated by performance on two secondary tasks. Experiment 1 suggested that road situation is a major determinant of visual and mental workload of the driver and that the processing resources of older drivers are somewhat more limited than those of younger and middle-aged drivers. Familiarity with the area of driving (when guided) and time of day (associated with traffic density) showed no secondary task effects.

Effects of head-slaved and peripheral displays on lane-keeping performance and spatial orientation.

To improve the efficiency of images presented in low-cost vehicle simulators, the virtual viewing direction (i.e., the direction in which the image is rendered) can be head-slaved, the display can be surrounded with a less detailed peripheral image, or both.

Fidelity of three-dimensional-sound reproduction using a virtual auditory display.

The fidelity of reproducing free-field sounds using a virtual auditory display was investigated in two experiments. In the first experiment, listeners directly compared stimuli from an actual loudspeaker in the free field with those from small headphones placed in front of the ears. Headphone stimuli were filtered using head-related transfer functions (HRTFs), recorded while listeners were wearing the headphones, in order to reproduce the pressure signatures of the free-field sounds at the eardrum.

Influence of attentional capture on oculomotor control.

Previous research has shown that when searching for a color singleton, top-down control cannot prevent attentional capture by an abrupt visual onset. The present research addressed whether a task-irrelevant abrupt onset would affect eye movement behavior when searching for a color singleton. Results show that in many instances the eye moved in the direction of the task-irrelevant abrupt onset.

Influence of body roll on visually induced sensations of self-tilt and rotation.

Illusory self-tilt and illusory self-motion (vection) produced by rotation of a 360 degrees visual scene about the subject's roll axis was measured as a function of the presence or absence of actual rotation of the subject during acceleration of the visual scene. Rotation of the subject to a tilt of 15 degrees was at two levels of acceleration (onset) and with or without a delay between initial rotation and subsequent return (washout) to the vertical position. In one set of conditions, visual motion and subject motion were in opposite directions (concordant) and in another set they were in the same direction (discordant).

Finger cold-induced vasodilation during mild hypothermia, hyperthermia and at thermoneutrality.

Background: Exposure of the fingers to severe cold leads to cold-induced vasodilation (CIVD). The influence of ambient temperature on the CIVD-response is well understood and documented, but the response of CIVD to hyperthermia and mild hypothermia has rarely been investigated.

Methods: To investigate the influence of body thermal status on the CIVD response, eight subjects immersed their right hand in 5 degrees C water for 40 min during mild hypothermia (C), thermoneutrality (N) and hyperthermia (W).

A comparison of different ways to approximate time-to-line crossing (TLC) during car driving.

Three experiments are presented in which the accuracy of different methods to approximate time-to-line crossing is assessed the first experiment TLC was computed, using a trigonometric method, during normal driving while the vehicle stayed in lane. The minima of TLC were compared with two approximations and it was found computing TLC as lateral distance divided by lateral velocity gave poor results. It was concluded that this simple approximation is not suitable for measuring TLC minima in studies of driver behaviour.

Contribution of the otoliths to the human torsional vestibulo-ocular reflex.

The dynamic contribution of the otolith organs to the human ocular torsion response was examined during passive sinusoidal body roll about an earth-horizontal axis (varying otolith inputs) and about an earth-vertical axis (invariant otolith inputs). Torsional eye movements were registered in 5 subjects by means of video-oculography. At a fixed amplitude of 25 degrees, the stimulus frequency was varied from 0.

Attentional effects on preattentive vision: spatial precues affect the detection of simple features.

Most accounts of visual perception hold that the detection of primitive features occurs preattentively, in parallel across the visual field. Evidence that preattentive vision operates without attentional limitations comes from visual search tasks in which the detection of the presence of absence of a primitive feature is independent of the number of stimuli in a display. If the detection of primitive features occurs preattentively, in parallel and without capacity limitations, then it should not matter where attention is located in the visual field.

Preventing drowsiness accidents by an alertness maintenance device.

The reported experiment investigated in an advanced driving simulator whether drivers' alertness can be maintained in drowsiness-inducing conditions by a special game-like system, a 'gamebox'. Drowsiness was assessed by self-rating and eye-closures. Mental effort was assessed by a subjective workload rating scale and by a physiological measure (the 0.

Coriolis effects and motion sickness modelling.

Coriolis effects are notorious in relation to disorientation and motion sickness in aircrew. A review is provided of experimental data on these Coriolis effects, including the modulatory effects of adding visual or somatosensory rotatory motion information. A vector analysis of the consequences of head movements during somatosensory, visual and/or vestibular rotatory motion stimulation revealed that the more the sensed angular velocity vector after the head movements is aligned with the gravitoinertial force vector, the less nauseating effects are experienced.

Modelling motion sickness and subjective vertical mismatch detailed for vertical motions.

In an attempt to predict the amount of motion sickness given any kind of motion stimulus, we describe a model using explicit knowledge of the vestibular system. First, the generally accepted conflict theory is restated in terms of a conflict between a vertical as perceived by the sense organs like the vestibular system and the subjective vertical as determined on the basis of previous experience. Second, this concept is integrated with optimal estimation theory by the use of an internal model.

Contributions of roll and pitch to sea sickness.

The purpose of this study was to test the traditional assumption that sea sickness is uniquely provoked by heave motion characteristics, with pitch and roll movements being ineffective. In an experiment with a ship motion simulator, subjects were exposed to pitch and roll motions in combination with rather weak heave motions that have no motion sickness-inducing potential. Very high levels of motion sickness were observed (with a motion sickness rating scale) in almost 50% of our subjects.

Roll motion stimuli: sensory conflict, perceptual weighting and motion sickness.

In an experiment with 17 subjects, interactions of visual roll motion stimuli and vestibular body tilt stimuli were examined in determining the subjective vertical. Interindividual differences in weighting the visual information were observed, but in general, visual and vestibular responses added in setting the vertical. Despite the conflicting sensory information, motion sickness was not reported apart from one subject on one single occasion.